Paper feed mechanism for a printing calculating or like machine



Dec. 19, 1967 GASSINO ETAL PAPER FEED MECHANISM FOR A PRINTINGCALCULATING OR LIKE MACHINE Filed April 11, 1966 2 Sheets-Sheet l Dec.19, 1967 T. GASSINO ETAL PAPER FEED MECHANISM FOR A PRINTING CALCULATINGOR LIKE MACHINE Filed April 11, 1966 2 Sheets-Sheet 2 INVENTORS TERESIOGASSINO LORENZINO BERTINO BY 2%;-

A NT

United States Patent ABSTRACT (3F THE DISCLQSURE A paper feed mechanismfor a printing machine comprises a platen rotated before the printing inone direction retracting said paper to a printing position and rotatedafter the printing in the opposite direction advancing the paper to areading position. The platen is secured to a ratchet wheel engaged by aspring urged locking member reciprocable to rotate the platen. Anintercepting member arrests the ratchet wheel after being rotated to theprinting position while the locking member continues its stroke at leastone line farther. After printing, the intercepting member releases theratchet wheel, and the locking member rotates the platen in the oppositedirection advancing the last printed line to the reading position.

This invention relates to a paper feed mechanism for a printingcalculating or like machine, comprising a platen adapted to be rotatedbefore the printing in a predetermined direction a plurality of linespaces for retracting said paper and to be rotated after the printing inan opposite direction for advancing said paper at least one line spacefarther than said plurality of line spaces and a ratchet wheel bodilyrotatable with said platen and normally locked by a spring urged lockingmember.

There are known paper feed mechanisms of this type, wherein the lastprinted line is brought automatically above the upper edge of theconventional tearing ruler. The purpose of these mechanisms is toretract and then to advance said paper so that the amounts printed onthe tape are clearly visible after each operation of the machine and sothat the paper may be cut by said tearing ruler directly in the reachedposition without interfering with the legibility of the printed amounts.All these known mechanisms are provided with different means forrotating the platen in the two directions, whereby the mechanisms arerelatively intricate.

This disadvantage is obviated by the paper feed mechanism according tothe invention, which is characterized by cyclically operating means formoving said locking member through a predetermined forward stroke beforethe printing, said locking member being adapted to rotate yieldably saidratchet wheel in said predetermined direction, an intercepting memberbeing provided for arrest ing said ratchet wheel after being rotatedsaid plurality of line spaces in said predetermined direction, whilesaid locking member completes said forward stroke independently fromsaid ratchet wheel, restoring means being effective after the printingfor returning said locking member through a rearward stroke equal tosaid forward stroke to rotate said ratchet wheel in said oppositedirection said farther line space.

This and other characteristics of the invention will become apparentfrom the following detailed description of a preferred embodimentthereof, and from the accompanying drawings wherein:

FIG. 1 is a left hand longitudinal partial sectional view of a paperfeed mechanism according to the invention embodied in a printingcalculating machine;

FIG. 2 is a partial front view of the mechanism;

FIG. 3 is a left hand longitudinal sectional view taken according to theline IIIIII of FIG. 2;

FIG. 4 is a left hand longitudinal sectional view taken according to theline IV-IV of FIG. 2;

FIG. 5 is a left hand longitudinal view of a detail of the mechanism;

FIG. 6 is a longitudinal view of another detail of the mechanism.

With reference to FIG. 1, the numeral 11 indicates a conventional platen11 secured to a shaft 12 rotatably mounted on the machine frame andadapted to support a paper strip 10. A printing device compris'mg a setof slides 16, each one carrying a typewheel 13, is adapted to printsimultaneously on the paper 10 under the control of a universal bar 17reciprocated in a known manner by a cyclically rotating shaft 18, whichrepresents the main shaft of the machine. Secured to each typewheel 13is a pinion 14 steadily engaged by a vertical rack 15, the movement ofwhich is controlled by a corresponding actuator not shown in thedrawings.

In the rest position the printed amount is visible above the upper edgeof a tearing ruler 19 (FIG. 2) having a pin 22 cooperating with atoothed slot 20 provided on the paper release frame 21 and adapted to betransversely displaced by manually operating a lug 23 integral with theruler 19. The upper edge of the ruler 19 is provided with a set ofprojections 24 adapted to provide the cut edge of the paper with a setof notches. The projections 24 are distanced according to threetypewheels 13 to facilitate the reading of the printed amount bysubdividing the same in groups of orders.

Secured to the shaft 18 is a cam 26 (FIG. 1) adapted to cooperate with abail 27 fulcrumed on a stationary shaft 28. Linked with an arm 29 of thebail 27 is a link 31, which is provided with an arcuate slot 32 engagedby a pin 33 of a lever 36 rotatably mounted on the shaft 12. The slot 32has a predetermined length corresponding, for instance, to five linespaces. At rest the lever 36 is urged by a spring 37 to cause the pin 33to contact the lower edge of said slot 32 as shown in FIG. 1.Furthermore, secured to the lever 36 is a pivot 41, pivotally mounting alocking member 42 which is urged by a spring 44 to engage a ratchetwheel 46 intergral with a sleeve 47 secured to the shaft 12. The teethof the wheel 46 have a pitch corresponding to a line space.

Fulcrumed on the pivot 41 is also a second locking member 43 (FIG. 4)urged by a spring 48 to engage one of three notches 49, 50, 51 providedon a cam shaped sector 52 idly mounted on the shaft 12. Normally, themember 43 engages the intermediate notch 50 as shown in FIG. 4.

A lever 53 (FIG. 1) is adapted to be manually or automatically locatedin one of a pair of positions according to the character of theoperation of the machine, i.e. whether it is a printing cycle or anon-printing cycle, in a known manner and is provided with a pin 54adapted to cooperate with a shoulder 56 of a slide 57.

Normally in the printing cycles, the lever 53 is located in the positionshown in FIG. 1, and therefore the pin 54 does not engage the shoulder56. A spring 61 urges the slide 57 to contact with a shoulder 58 a pin59 secured on a slide 62. In the calculating printing cycles a pin 63locates the slide 62 in the position of FIG. 1, whereas in the totaltaking printing cycles the pin 63 is displaced rearwards in a knownmanner to cause the slides 62 and 57 to be moved rearwards.

The slide 57 is linked with a lever 64 fulcrumed on a stationary shaft67 and is provided with a pin 69 engaging a slot 71 provided on a forkedslide 72. The slide 72 is fulcrumed on an arm 73 of the bail 27, and isalso proa vided with font shoulders 74, 76 and 77, 78 two by twosymmetrically located with respect to the stationary shaft 67. Theshoulders 74, 76, and the shoulders 77, 78 respectively, are adapted tocooperate with a pair of lugs 79 and 81 of a lever 82 fulcrumed on thestationary shaft '67. Furthermore the lever 82 is connected through arod 84 (FIG. 4) to the sector 52.

The paper feed mechanism comprises an intercepting lever 87 fulcrumed onthe shaft 67 and having a bent lug 86' and urged by a spring 88 toContact the sector 52. The bent lug 86 is normally located at a distancefrom a slope 89 of the sector 52 corresponding to four line spaces.

Fulcrumed on the shaft 67 is also a bail 93 (FIG. 3) having a first lug92 adapted to cooperate with a ratchet Wheel 91 similar to the wheel 46and integral with the sleeve 47, so that both the wheels 46 and 91 arebodily rotatable with the shaft 12. Furthermore the bail 93 is providedwith a second bent lug 95 urged by a spring 94 to sense the paper 10above the upper edge of the tearing ruler 19.

The paper 10 may be introduced into a conventional paper-guide frame 96(FIG. 5) secured to a shaft 116 rotatably mounted on the machine frame.Secured to the shaft 116 is also a lever 117 having a pin 118 urged by aspring 122 to contact a cam shaped edge of the frame 21 comprising atapered portion 119 and a horizontal portion 120. The frame 96 isprovided with a pair of notches engaging a shaft 97 secured to threepaper feed rollers 98. Secured to the shaft 97 is also a pinion 99 (FIG.6) meshing with a pinion 101 provided with two radial oppositeprojections 107 (FIG. 2) engaging two corresponding notches 106 of aring 102 also provided on the opposite side with two other notches 103shifted 90 degrees with respect to the notches 106 engaged by twoprojections 104 of the wheel 91. Thus the retracting and advancingrotation of the wheels 46 and 91 is transmitted to the pinions 101 and99 through the ring 102. The pinion 101 is rotatably mounted on a hub109 integral with an arm 108 (FIG. 6) provided with a slot 111 enteredby the shaft 12. The arm 108 is also provided with a circular hole 112entered by a circular disk 110 integral with the pinion 99.

The paper feed mechanism operates as follows:

As already mentioned, during a calculating printing cycle, the lever 53(FIG. 1), the slides 57 and 62 remain in the shown position and thelever 64 is not rocked. During the cycle of the main shaft 18, the cam26 rocks clockwise the bail 27, thus displacing the link 31 and theslide 72 upwards, but the lugs 79 and 81 are not affected by the slide72. Therefore the sector 52 (FIG. 4) remains in the position shown onFIG. 4. In turn the link 31 (FIG. 1) rocks the lever 36 clockwisetogether with the rod 41, whereby the two locking members 42 and 43(FIG. 4) are rotated clockwise. The locking member 42 (FIG. 1) yieldablyrotates the ratchet wheel 46 clockwise bodily with the sleeve 47 and theplaten 11, whereas the locking member 43 (FIG. 4) yieldably rotates thesector 52 clockwise.

When the sector 52 has been rotated four line spaces, the slope 89 ofthe sector 52 causes the lug 86 of the lever 87 to engage a tooth of theratchet wheel 46, thus locking the shaft 12, the platen 11 and the paper(FIG. 2) while the two locking members 42 and 43 and the sector 52 arerotated a further line space, the locking member 42 tripping a tooth onthe wheel 46. The paper 10 has been thus retracted four line' spaces,while the locking member 42 completes its stroke of five line spaces,independently from the ratchet wheel 46.

After the typewheels 13 (FIG. 1) print the set up amount on the paper10, the cam 26 causes the bail 27 to return counterclockwise. The link31 and the slide 72 are restored and the lever 36 is restored by thespring 37 together with the locking members 42 and 43. The lockingmember 42 now rotates the ratchet wheel 46, the sleeve 47, the platen 11and the paper 10 five line spaces counterclockwise.

It is thus clear that the cyclically operating means 31, 36, are adaptedto reciprocate the locking member 42 through a predetermined stroke torotate yieldably the ratchet wheel 46 clockwise to retract the paperfour line spaces, and then to advance same five line spaces and that theintercepting member 86 (FIG. 4) locks the ratchet wheel after beingrotated said four line spaces in the retracting direction.

Now, supposing that a total key is depressed, the pin 63 (FIG. 1) isdisplaced rearwards, thus causing the spring 61 to displace the slides57 and 62 rearwards, and to rock the lever 64 counterclockwise.Therefore, the pin 69 of the lever 64 rocks the slide 72 clockwise,whereby the shoulder '76 is located in front of the lug 79 of the lever82. When the bail 27 is rocked clockwise the shoulder 76 (FIG. 1) of theslide 72 encounters the lug 79 and rocks the lever 82 clockwise. The rod84 thus rotates the sector 52 (FIG. 4) one line space clockwise withrespect to the wheel 46. Thus the locking member 43 is caused to engagethe notch 49 of the sector 52. Upon printing the total the paper 10 isadvanced five line spaces as in the above case, while the sector 52 isreturned also five line spaces and locates the slope 89 at a distance ofthree spaces from the lug 86. At the end of the total taking cycle, thepin 63 (FIG. 1), the slides 62 and 57 are restored causing the lever 64to return the slide 72 in the central position shown on FIG. 1.

If now a new calculating printing cycle is effected the sector 52 (FIG.4) upon being rotated clockwise three line spaces causes the lug 86 tolock the wheel 46 and the platen 11, while the locking member 42 tripstwo teeth on the wheel 46. The shoulder 77 of the slide 72 (FIG. 1)encounters now the lug 81 of the lever 82, which is thus returned in theposition shown in FIG. 1. The lever 82 thus causes the sector 52 (FIG.4) to rotate one line space counterclockwise with respect to the wheel46, whereby the locking member 43 engages again the notch 50. Then thetwo locking members 42 and 43 (FIGS. 1 and 4) perform their returnstroke for advancing the paper five line spaces and consequently theforegoing printed total and the new printed amounts are distanced twoline spaces instead of one line space. The lug 66 contacts the sector 52again at a distance of three line spaces from the slope 89, thuspredisposing one line space for the next printing cycle.

Supposing now that after a printing cycle, a non-printing cycle iseffected. Then the lever 53 (FIG. 1) is rocked counterclockwise andthrough the pin 54 and the shoulder 56 displaces the slide 57 forwards,thus rocking the lever 64 clockwise. Consequently, the slide 72 isrocked counterclockwise and locates the shoulder 78 on the path of thelug 81 of the lever 82. During the first part of this cycle the paper isretracted four line spaces and the shoulder 78 encounters the lug 81,thus rocking the lever 82 counterclockwise and the sector 52 (FIG. 4)counterclockwise one line with respect to the locking member 43 whichnow engages the notch 51. Then in the second part of this cycle thepaper is advanced five line spaces, but the sector 52 locates the slope89 at a distance of four line spaces from the lug 86. i

If then a calculating printing cycle is effected the lever 53 (FIG. 1),the slides 62 and 57, the lever 64, and the slide 72 are restored to theposition shown on FIG. 1. In the first art of this calculating printingcycle the sector 52 (FIG. 4) is rotated clockwise, but the lug 86 of theintercepting lever 87 locks the platen 11 after five retracting linespaces, whereby the locking member trips no tooth on the wheel 46. Theshoulder 74 of the slide 72 (FIG. 1) encounters now the lug 79 of thelever 82 which is returned to the position shown on FIG. 1, thusrotating the sector 52 (FIG. 4) one line space clockwise with re-v spectto the locking member 43 which engages again the notch 50.

When the two locking members 42 and 43 (FIGS. 1 and 4) are returnedcounterclockwise, the paper is advanced five line spaces andconsequently the new printed amount and the amount printed before thenonprinting cycle are distanced one line space only. The lug 86 contactsagain the sector 52 at a distance of three line spaces from the slope89, thus predisposing one line space for the next printing cycle.

Supposing now that a total taking cycle is requested after anon-printing cycle. During the retracting stroke of the paper, theshoulder 76 of the slide 72 encounters the lug 79 of the lever 82 whichwas rocked counterclockwise. The lever 82 is thus rotated clockwise,thus rocking the sector 52 clockwise two line spaces with respect to thelocking member 43 which engages now the notch 49 of the sector 52. Atthe end of the total taking cycle the lug 86 contacts the sector 52 at adistance of two line spaces from the slope 89.

Supposing that after a printing cycle the paper is cut by the tearingruler 19 (FIG. 2). Now no paper is sensed by the lug 95 (FIG. 3),whereby the spring 94 causes the lever 93 to lock with the lug 92 theratchet wheel 91. Consequently, the retracting stroke of the paper isprevented, thus avoiding the typewheels 13 to print a new amount near tothe paper edge and causing the locking member 42 (FIG. 1) to trip fiveline spaces on the teeth of the wheel 46. During the returning stroke ofthe locking members 42 and 43, the paper tape is advanced five linespaces and engages again the lug 95 (FIG. 3), whereby the lever 93 isrocked counterclockwise and disengages the lug 92 from the wheel 91.

In all the hereinabove described cases the wheel 91, through the twoprojections 104 and the notches 103 rocks the ring 102, which throughthe notches 106 and the projections 107 rocks the pinion 101. The pinion99 is thus rotated together with the shaft 97, and the paper feedrollers 98, synchronously with the platen 11, whereby the paper 10 ismoved through the retracting and advancing stroke both by the platen 11and the feed rollers 98.

When the paper is to be introduced between the paperguide-frame 96 andthe platen 11 (FIG. 5), the frame 21 is manually displaced forwardsbodily with the tearing ruler 19 by sliding with a pair of slots 125 onthe universal bar 17. The portion edge 119 of the frame 21 causes thearm 117 to rock against the urge of the spring 122, whereby thepaper-guide frame 96 is removed from the platen 11 bodily with the arm117 and the rollers 98.

During the introduction of the paper the frame 21 is held in theforwards displaced position by the arm 117 which engages the horizontaledge 120 of the frame 21. After the introduction of the paper a printingcycle may be started without returning the frame 21 rearwards. In fact,immediately before the printing of the typewheels 13, the universal baris moved rearwards and automatically restores the frame rearwards.

When the frame 96 is removed from the platen 11 the shaft 97, throughthe pinion 99 and the hole 112 displaces the arm 108 (FIG. 6) downwards,whereby the pinion 101 is also displaced downwards through theprojection 109. Therefore the pinion 101 continues to engage the ring102 and the two pinions 101 and 99 remain mutally engaged even if themutual position of the two shafts 12 and 97, i.e. of the platen 11 andthe feed roller 98, is changed according to the paper thickness.

It is intended that modifications, improvements and additions of partsmay be made to the described paper feed mechanism without departing fromthe scope of the invention as defined by the appended claims.

What we claim is:

1. In a paper feed mechanism for a printing calculating or like machine,having a platen adapted to be rotated before the printing in apredetermined direction a plurality of line spaces for retracting saidpaper and to be rotated after the printing in an opposite direction foradvancing said paper at least one line space farther than said pluralityof line spaces, a ratchet wheel bodily rotatable with said platen, and aspring urged locking member normally locking said ratchet wheel, thecombination comprising:

(a) cyclically operating means for moving said locking member through apredetermined forward stroke before the printing,

(b) means for causing said locking member to yieldably rotate saidratchet wheel in said predetermined direction,

(c) an intercepting member for arresting said ratchet wheel after beingrotated said plurality of line spaces in said predetermined direction,said locking member being adapted to complete its said forward strokeindependently from said ratchet wheel,

(d) and restoring means effective after the printing for returning saidlocking member through a rearward stroke equal to said forward stroke torotate said ratchet wheel in said opposite direction said farther linespace.

2. In a paper feed mechanism for a printing calculating or like machine,having a platen adapted to be rotated before the printing in apredetermined direction a plurality of line spaces for retracting saidpaper and to be rotated after the printing in an opposite direction foradvancing said paper at least one line space farther than said pluralityof line spaces, a ratchet wheel bodily rotatable with said platen, and afirst spring urged locking member normally locking said ratchet wheel,the combination comprising:

(a) a cyclically operating means for moving said first locking memberthrough a predetermined forward stroke before the printing,

(b) means for causing said first locking member to yieldably rotate saidratchet wheel in said predetermined direction,

(c) an intercepting member for arresting said ratchet wheel after beingrotated said plurality of line spaces in said predetermined direction,said first locking member being adapted to complete said forward strokeindependently from said ratchet wheel,

(d) restoring means effective after the printing for returning saidlocking member through a rearward stroke equal to said forward stroke torotate said ratchet wheel in said opposite direction said farther linespace,

(e) a cam for controlling said intercepting member,

(f) a second spring urged locking member normally locking said cam andbodily reciprocable with said first locking member, said second lockingmember being adapted to yieldably operate said cam in both saiddirections,

(g) and settable means for setting said second locking member in avariable relationship with said cam.

3. In a paper feed mechanism for a printing calculating or like machine,having a platen adapted to be rotated before the printing in apredetermined direction a plurality of line spaces for retracting saidpaper and to be rotated after the printing in an opposite direction foradvancing said paper at least one line space farther than said pluralityof line spaces, a ratchet wheel bodily rotatable with said platen, and afirst spring urged lock- 5 ing member normally locking said ratchetwheel, the

combination comprising:

(a) cyclically operating means for moving said locking member through apredetermined forward stroke before the printing,

(b) means for causing said first locking member to yieldably rotate saidratchet wheel in said predetermined direction,

(c) an intercepting member being provided for arresting said ratchetwheel after being rotated said plurality of line spaces in saidpredetermined direction,

said first locking member being adapted to complete said forward strokeindependently from said ratchet wheel,

(d) restoring means effective after the printing for returning saidlocking member through a rearward stroke equal to said forward stroke torotate said ratchet wheel in said opposite direction said farther linespace,

(e) a cam for controlling said intercepting member,

(f) a second spring urged locking member normally locking said cam andbodily reciprocated with said first locking member,

(g) said second locking member being adapted to yieldably rotate saidcam in both said directions,

(h) and settable means selectively operated simultaneously with saidcyclically operating means for setting said cam in a predeterminedrelationship with respect to said second locking member, whereby saidintercepting member in the next following cycle will arrest said ratchetwheel according to said predetermined relationship.

4. In a paper feed mechanism for a printing calculating or like machine,having a platen adapted to be rotated before the printing in apredetermined direction a plurality of line spaces for retracting saidpaper and to be rotated after the printing in an opposite direction foradvancing said paper at least one line space farther than said pluralityof line spaces, a ratchet wheel bodily rotatable with said platen, andby a first spring urged locking member normally locking said ratchetwheel, the combination comprising:

(a) a cyclically operating means for moving said first locking memberthrough a predetermined forward stroke before the printing,

(b) means causing said first locking member to yieldably rotate saidratchet Wheel in said predetermined direction,

(c) an intercepting member for arresting said ratchet wheel after beingrotated said plurality of line spaces in said predetermined direction,said first locking member being adapted to complete said forward strokeindependently from said ratchet wheel,

(d) restoring means effective after the printing for returning saidlocking member through a rearward stroke equal to said forward stroke torotate said ratchet wheel in said opposite direction said farther linespace,

(e) a cam for controlling said intercepting member,

(f) a second spring urged locking member normally locking said cam andbodily reciprocable with said first locking member, said second lockingmember being adapted to yieldably operate said cam in both saiddirections,

(g) a pair of diametrically opposite elements secured to said cam,

(h) and a pair of cyclically operated pawls adapted to engageselectively said elements for setting said second locking member in saidvariable relationship with said cam.

5. In a paper feed mechanism for a printing calculating or like machine,having a platen adapted to be rotated in a predetermined direction aplurality of line spaces for retracting said paper and to be rotatedafter the printing in an opposite direction for advancing said paper atleast one line space farther than said plurality of line spaces, aratchet wheel bodily rotatable with said platen, and a spring urgedlocking member normally locking said ratchet wheel, the combinationcomprising:

(a) a cyclically operating means for moving said locking member througha predetermined forward stroke before the printing,

(b) means for causing said locking member to yieldably rotate saidratchet wheel in said predetermined direction, I

(c) an intercepting member for arresting said ratchet wheel after beingrotated said plurality of line spaces in said predetermined direction,said locking member being adapted to complete said forward strokeindependently from said ratchet wheel,

(d) restoring means effective after the printing for returning saidlocking member through a rearward stroke equal to said forward stroke torotate said ratchet wheel in said opposite direction said farther linespace.

(e) a sensing member for sensing the paper substantially incorrespondence with the last printed line,

(f) and an intercepting element connected to said sensed member forarresting said ratchet wheel at the beginning of the rotation in saidpredetermined direction in the case no paper is sensed by said sensingmember.

6. In a paper feed mechanism for a printing calculating or like machine,having a platen adapted to be rotated in a predetermined direction aplurality of line spaces for retracting said paper and to be rotatedafter the printing in an opposite direction for advancing said paper atleast one line space farther than said plurality of line spaces, paperfeed rollers yieldably contacting said platen, a ratchet Wheel bodilyrotatable with said platen, and a spring urged locking member normallylocking said ratchet wheel, the combination comprising:

(a) cyclically operating means for moving said locking member through apredetermined forward stroke before the printing,

(b) means for causing said locking member to yieldably rotate saidratchet wheel in said predetermined direction,

(c) an intercepting member for arresting said ratchet Wheel after beingrotated said plurality of line spaces in said predetermined direction,said locking member being adapted to complete said forward strokeindependently from said ratchet wheel,

(d) restoring means effective after the printing for returning saidlocking member through a rearward stroke equal to said forward stroke torotate said ratchet wheel in said opposite direction said farther linespace,

(e) rotation transmitting means for causing said platen to synchronouslyrotate said rollers in opposite directions, whereby said paper is alwaysmoved by the combined action of said platen and said rollers,

(f) and connecting means for enabling said transmitting means to beeffective independently from the mutual distance between said platen andsaid rollers.

References Cited UNITED STATES PATENTS 2,297,743 10/ 1942: Carroll eta1. 235--60.51 3,075,626 1/1963 Schultz 235-60.51

RICHARD B. WILKINSON, Primary Examiner.

L. FRANKLIN, Assistant Examiner.

1. IN A PAPER FEED MECHANISM FOR A PRINTING CALCULATING OR LIKE MACHINE,HAVING A PLATEN ADAPTED TO BE ROTATED BEFORE THE PRINTING IN APREDETERMINED DIRECTION A PLURALITY OF LINE SPACES FOR RETRACTING SAIDPAPER AND TO BE ROTATED AFTER THE PRINTING IN AN OPPOSITE DIRECTION FORADVANCING SAID PAPER AT LEAST ONE LINE SPACE FARTHER THAN SAID PLURALITYOF LINE SPACES, A RATCHET WHEEL BODILY ROTATABLE WITH SAID PLATEN, AND ASPRING URGED LOCKING MEMBER NORMALLY LOCKING SAID RATCHET WHEEL, THECOMBINATION COMPRISING: (A) CYCLICALLY OPERATING MEANS FOR MOVING SAIDLOCKING MEMBER THROUGH A PREDETERMINED FORWARD STROKE BEFORE THEPRINTING, (B) MEANS FOR CAUSING SAID LOCKING MEMBER TO YIELDABLY ROTATESAID RATCHET WHEEL IN SAID PREDETERMINED DIRECTION, (C) AN INTERCEPTINGMEMBER FOR ARRESTING SAID RATCHET WHEEL AFTER BEING ROTATED SAIDPLURALITY OF LINE SPACES IN SAID PREDETERMINED DIRECTION, SAID LOCKINGMEMBER BEING ADAPTED TO COMPLETE ITS SAID FORWARD STROKE INDEPENDENTLYFROM SAID RATCHET WHEEL, (D) AND RESTORING MEANS EFFECTIVE AFTER THEPRINTING FOR RETURNING SAID LOCKING MEMBER THROUGH A REARWARD STROKEEQUAL TO SAID FORWARD STROKE TO ROTATE SAID RATCHET WHEEL IN SAIDOPPOSITE DIRECTION SAID FARTHER LINE SPACE.